MAX9724A_09 Datasheet, PDF (1/19 Pages) Maxim Integrated Products – 60mW, DirectDrive, Stereo Headphone Amplifier with Low RF Susceptibility and Shutdown

19-3597; Rev 6; 3/09
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60mW, DirectDrive, Stereo Headphone Amplifier
with Low RF Susceptibility and Shutdown
General Description
The MAX9724A/MAX9724B stereo headphone ampli-
fiers are designed for portable equipment where board
space is at a premium. These devices use a unique,
patented^† DirectDrive^® architecture to produce a
ground-referenced output from a single supply, elimi-
nating the need for large DC-blocking capacitors, sav-
ing cost, board space, and component height. The
MAX9724 suppresses RF radiation received by input
and supply traces acting as antennas and prevents the
amplifier from demodulating the coupled noise. The
MAX9724A offers an externally adjustable gain while
the MAX9724B has an internally preset gain of -1.5V/V.
The MAX9724A/MAX9724B deliver up to 60mW per
channel into a 32Ω load and have low 0.02% THD+N.
An 80dB at 1kHz power-supply rejection ratio (PSRR)
allows these devices to operate from noisy digital sup-
plies without an additional linear regulator.
Comprehensive click-and-pop circuitry suppresses
audible clicks and pops on startup and shutdown.
The MAX9724A/MAX9724B operate from a single 2.7V
to 5.5V supply, consume only 3.5mA of supply current,
feature short-circuit and thermal-overload protection,
and are specified over the extended -40°C to +85°C
temperature range. The devices are available in tiny 12-
bump UCSP™ (1.5mm x 2mm) and 12-pin thin QFN
(3mm x 3mm x 0.8mm) packages.
Applications
Cellular Phones
DVD Players
MP3 Players
Smart Phones
Notebook PCs
PDAs
Handheld Gaming Consoles
DirectDrive is a registered trademark of Maxim Integrated
Products, Inc.
Features
o Improved RF Noise Rejection (Up to 67dB Over
Typical Amplifiers)
o No Bulky DC-Blocking Capacitors Required
o Low-Power Shutdown Mode, < 0.1µA
o Adjustable Gain (MAX9724A) or Fixed -1.5V/V
Gain (MAX9724B)
o Low 0.02% THD+N
o High PSRR (80dB at 1kHz) Eliminates LDO
o Integrated Click-and-Pop Suppression
o 2.7V to 5.5V Single-Supply Operation
o Low Quiescent Current (3.5mA)
o Available in Space-Saving Packages
12-Bump UCSP (1.5mm x 2mm)
12-Pin Thin QFN (3mm x 3mm x 0.8mm)
Ordering Information
PART
GAIN PIN-
(V/V) PACKAGE
TOP
MARK
MAX9724AEBC+TG45 Adj. 12 UCSP
+ADH
MAX9724AETC+
Adj. 12 TQFN-EP* +AAT
MAX9724BEBC+TG45 -1.5 12 UCSP
+ADI
MAX9724BETC+
-1.5 12 TQFN-EP* +AAU
Note: All devices specified over the -40°C to +85°C operating
range.
+Denotes lead(Pb)-free/RoHS-compliant package.
T = Tape and reel.
*EP = Exposed paddle.
Pin Configurations appear at end of data sheet.
†_{U.S. Patent# 7,061,327}
UCSP is a trademark of Maxim Integrated Products, Inc.
Block Diagrams
LEFT
AUDIO
INPUT
SHDN
RIGHT
AUDIO
INPUT
MAX9724A
DirectDrive OUTPUTS
ELIMINATE DC-BLOCKING
CAPACITORS
LEFT
AUDIO
INPUT
SHDN
RIGHT
AUDIO
INPUT
MAX9724B
DirectDrive OUTPUTS
ELIMINATE DC-BLOCKING
CAPACITORS
FIXED GAIN ELIMINATES
EXTERNAL RESISTOR
NETWORK
________________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.